diff options
| -rw-r--r-- | src/asm2wasm.h | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/src/asm2wasm.h b/src/asm2wasm.h index c28d60a75..498e5fc20 100644 --- a/src/asm2wasm.h +++ b/src/asm2wasm.h @@ -967,15 +967,35 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) { return ret; } else if (what == SWITCH) { // XXX switch is still in flux in the spec repo, just emit a placeholder -#ifndef __EMSCRIPTEN__ - return allocator.alloc<Nop>(); // ignore in reference interpreter -#else IString name = getNextId("switch"); breakStack.push_back(name); auto ret = allocator.alloc<Switch>(); ret->name = name; - ret->value = process(ast[1]); + ret->value = process(ast[1]); + assert(ret->value->type == i32); Ref cases = ast[2]; + bool seen = false; + int min = 0; // the lowest index we see; we will offset to it + for (unsigned i = 0; i < cases->size(); i++) { + Ref curr = cases[i]; + Ref condition = curr[0]; + if (!condition->isNull()) { + assert(condition[0] == NUM || condition[0] == UNARY_PREFIX); + int32_t index = getLiteral(condition).geti32(); + if (!seen) { + seen = true; + min = index; + } else { + if (index < min) min = index; + } + } + } + Binary* offsetor = allocator.alloc<Binary>(); + offsetor->op = BinaryOp::Sub; + offsetor->left = ret->value; + offsetor->right = allocator.alloc<Const>()->set(Literal(min)); + offsetor->type = i32; + ret->value = offsetor; for (unsigned i = 0; i < cases->size(); i++) { Ref curr = cases[i]; Ref condition = curr[0]; @@ -987,7 +1007,9 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) { } else { assert(condition[0] == NUM || condition[0] == UNARY_PREFIX); int32_t index = getLiteral(condition).geti32(); - assert(index >= 0); // TODO: apply an offset, and have an option to abort switching at all (or do it in emscripten?) + assert(index >= min); + index -= min; + assert(index >= 0); case_.name = getNextId("switch-case"); if (ret->targets.size() <= index) { ret->targets.resize(index+1); @@ -1009,7 +1031,6 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) { // finalize breakStack.pop_back(); return ret; -#endif } abort_on("confusing expression", ast); return (Expression*)nullptr; // avoid warning |